Electric switch



1944- R. N. THOMAS EI'AL 2,356,631

ELECTRIC SWITCH Filed Nov. 18, 1942 1 Inventors! 1 FQQ N. Thomas,

Thomas I. Maslin,

4/ by W 6 JM Their Attorney.

2,356,631 nmzo'rnrc s'rcn RoyN. Thomas, East Orange, and Thomas K. Maslin, Bloomfield, N. 3., assignors to General Electrio Company, a corporation of New York Application November 18 i942, serial No. 65,998 2 Claims. (Cl. 200 159) Our invention relates to electric switches, more particularly to electric switches of the push button type, and has for itgobjectfsimple and To provide for the latching of the plunger reliable meansforsedm the switch against i iii, a laterally extending recess '23 .is provided -operation by severe shocks. e in the plunger it on its side adjacent the auxil- -.In carrying out our invention lnone form, iary plunger into which the inner end of the we provide a latch for locking the switch memauxiliary plunger normally extends, as shownrin :ber together with a push button operating mem- Fig. 1, thereby to latch the main plunger-in its her which when depressed first withdraws the raised position. latch to release the'switch member, and then it To provide for the withdrawal oi the auxiloperates the switch member to another switchiary plunger is prior to depression of plunger in: position. it to its other switching position, the operating "For a more complete understanding of our button or knob 26 which is a hollow cylindrical invention, reference should be had to the acmember having a closed upper end is normally companying drawing in which Fig. lis a side 35 maintained slightly raised with respect to th elevation view partly in section of an electric main plunger ill by means of a helical spring switch embodying our invention; Fig. 2 is a 25. This spring is considerably weaker. than front elevation view of the device shown in the main spring it to provide for depression of Fig. 1; Fig. 3 is a view mainly in'section taken the plunger and compression of this spring withalong the line 33 of Fig. 2 looking in the out appreciable compression of. the spring it. direction of the arrows but showing the button It will be understood that this preliminary depressed to release the main plunger; while movement of the button 26 must be effected Fig. 4 is an exploded view showing details of without sumcient movement downward of .the the various parts. main plunger ill to cause the upper wall oi" the We have shown our invention in one form recess 23 to engage the auxiliary plunger i9 as applied to a push button switch of the type described and claimed in U. S. Patent 1,853,964, issued on April 12, 1932, to George H. Dorgeloh and Thomas I. Maslin. The device comprises a main operating plunger Ill slidably moun tew/Jls the button 24 is thus initially depressed, in an aperture ll provide i'or it; in asupport cam surfaces 28 and 2'l'on its lower edge en- 'l2 madezof electricallyinsulating material, prefstage the sides of a double -link 28 connecting erably a molded compound. A bridging 0011- the auxiliary plunger it with a pivot bracket tact member l3 made of suitable electrically 29. Thus it will be Observed that the button conducting material, such as copper, is mounted has a leng e ext n i r upri ht Sl 30. on the lower end of the plunger It in position the side walls of which at their lower ends emto engage and electrically connect together stabracethe bracket 29. When the button is detionary contacts I 4 and IS in its raised position pressed, the rounded lower ends 28 and 21 enor engage stationary contacts l6 and II in its gage respectively cam projections 30a (only one lowered position. Normally, the plunger and 40 of which is shown) on the two "sides of the link 28, This forces the lower end of the link bridging contact are maintained in their raised position by a helical spring l8, as shown in theoutward, the link moving in a counter-clockwise and apply a frictional binding action preventing withdrawal of the auxiliary plunger. Preferably as shown the button 24 is made of an electrically insulating molded compound.

drawing. This is a normal position 01 the Y direction asseen-in -Eigs.-L and 3; abOutiE Switch. and it i an iectilgyilinventionto pivot 3i on the bracket 29.. Thus, as shown provide mchmsmrar securing the plunger in Fig. 3, when the button has been depressed in this raised position against severe shocks. -far enough to engage the upper end of the main In accordance with our invention, w provide plunger, the auxiliary plunger is withdrawnfaran auxiliary plunger l9 which is slidably enough to tree the main plunger, 1. e, its inner mounted in a suitable aperture provided for it endis withdrawnfrom the aperture 2|. Furin a metal collar 20 having a central aperture ther. depression of the button now moves the 2| providing a sliding fit for the plunger-l0. main plunger downward and operates the switch At its upper end the collar 20 is provided with in the normal way. a counterbore 22 in which the lower end of when the button is released, the springs II the spring l8 extends and is seated on the and 25 return the button and main plunger to shoulder thereby formed. This collar is thus the positions shown in Fig. 1 whereupon the .Zecured in position igypumger id'and thespring 2 a,seo,es1

auxiliary plunger I9 is moved'into the recess 23 by a spring 32 which surrounds the pivot 3| and has its ends bearing on the link 28. g

It will beunderstood that the switch is ai- 01 our invention, it will be understood, course, that we do not wish to be limited thereto since many modifications may be made, and we therefore contemplate by the appended claims to cover fected by shocks only to the extent that the 5 .any such modifications as fall within the true main plunger is moved by the shock. Moreover, it is contemplated that the plunger normally will be in its raised position, as shown in Fig. 1, so that shocks tending to move the spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent 01 the United States is:

1. A switch comprising a movably mounted plunger upward will not aiIect it. Therefore, 10 switch member including an operating member the auxiliary plunger must latch the main plunger only against shocks which tend to move the main plunger downward-1. e., against shocks applied to the support I! in an upward director said switch member, a first relatively strong spring biasing said operating member to a predetermined position whereby said switch member is biased to a predetermined first switching position. Such shocks, however, also would move tion, a latch member normally engaging said opthe button 24 downward. 'Actually this movement is relative for it is the support which is moved directly by the shock, the parts tending to remain stationary by reason of their inertia.

Thus it might be inferred that the: button 24 Eighti "leshock far enough downerating member when said operating member is in said first position thereby to hold said operating member in said position in the event of a shock applied to said switch, a second operating member movably mounted on said first operating member, a second relatively weak spring between "ward to withdraw the aifillarfplufig". is said operating members for biasing said second action is prevented, however, by the fact that the button made oi a molded compound is much lighter in weight and consequently has much 25 member being movable first into engagementwith 7. less inertia than the main plunger and other parts carried by the plunger which tendto remain stationary. Moreover, a shock produces a binding or locking action between the main ember; in spaced relation with said first operating memberrsaid second pperating said first-operating member by the compression of said second spring without substantial movement of said first operating member against the force oi said first relatively strong spring, and

and auxiliary plungers preventing withdrawal .30 means operated by said secondoperating member of the auxiliary plunger by the button due to the efleot of the shock. Thus it will be understood that the main plunger tends to move downward relatively during shock whereby the upper wall or the recess 23 engages the auxiliary plunger with a very substantial force and thus creates enough friction between the auxiliary plunger and the parts engaged by it to prevent tends. vOn the end of the plunger is a nut 39 provided with an outer cylindrical electrically insulating portion 40 which fits slidably in a guide bore ll in the. support. By means or a helical spring H the bridging member normally is forced downward on the plunger Ill against a washer l3 resting on the nut 39. As shown, this spring 32 encircles the plunger I0 and has itsupper end "*Bmeinseamssner n which in turn is seated against shoulders on the plunger Ill, these shoulders being formed by making round the lower .end otthe plunger encircled by the spring and the washer 44 whereas the upper relishing part is square. This square cross section oi the plunger has a correspondin ly quare aperture I l for it in the support whereby the plunger is held against turning and likewise the collar 20 is provided with a square aperture to secure it against turning on the plunger.

While we'have shown a particular embodiment 00 member to release during such first movement for movingsaidlatcm member to release said first operating member after which said two operating members are movable together to compress said first spring and 31 move said switch member into a second switching position.

2. A switch comprising a movably mounted switch member including an operating member for said switch member, a first relatively strong 40 spring biasing said operating member to a predetermined position whereby said switch member is biased to a predetermined first switching position, a latch member normally engaging said operating member when said operating member is 45 in said first position thereby to hold said operating member in said position in the event of a shock appled to said switch, a second operatin member movably mounted on said first operating member, a second relatively weak spring between i9 said operating members for biasing said second aperture 33 through which the plunger ll exoperating mem ber in spaced relation with said first operating member, saidmecondJWating member being movable first into engagementwith said first operating member by the compression of said second spring without substantial movement of said first operating member against the force of said first relatively strong spring, and

means operated by said second operating member during such first movement for moving said latch after which said two operating members areniovable together to compress said first spring and move said switch member into a second switchngposition, said second operating member be- 05 ing constructed and arranged to have a relatively, 4

small inertia to prevent movement of said latch by said second operating member in response to a shock applied to said switch.

ROY N. THOMAS.

moms I. MASLIN.

said first operating member 

